CN1818208B - Paper conveying felt and press device of paper machine with the paper conveying felt - Google Patents

Abstract

A paper transporting felt includes a base layer, a first batt layer formed on a wet paper side surface of the base layer, a second batt layer formed on a press side surface of the base layer, a polymer elastic material impregnated in the base layer, the first batt layer and the second batt layer, and a wet paper contacting layer which is formed on a wet paper side surface of the first batt layer so as to come into direct contact with a wet paper, and includes a flexible resin material. The compressibility of the wet paper contacting layer is larger than that of a layer formed of the base layer, the first batt layer and the second batt layer.

Description

Paper conveying felt and press device of paper machine with the paper conveying felt

Cross References to Related Applications

This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-030300 filed on February 7, 2005, the entire contents of which are hereby incorporated by reference. the

technical field

The invention relates to a paper conveying felt and a press device of a paper machine provided with the paper conveying felt.

Background technique

Typically, a paper machine includes a wire section, a press section, and a dryer section. The wire mesh section, the press section, and the drying section are arranged in order along the wet paper transport direction. The wet paper is sequentially transported through the wet paper conveying parts in the wire mesh section, the press section, and the drying section. Conveyors) are dried. The pressing device arranged in the pressing section includes a plurality of pressing mechanisms arranged continuously along the wet paper conveying direction.

Each press mechanism comprises: a pair of paper conveying felts, which have an endless belt shape; and a pair of rollers (i.e., a roll press) or a roller and shoe (i.e., a shoe press) as press members longitudinally opposed to each other, A part of the pair of paper conveying felts is thereby sandwiched therebetween. By having the pair of rollers or rollers and shoes press the wet paper traveling by the paper conveying felt at the same speed and in the same direction as the paper conveying felt, moisture is squeezed out of the wet paper and absorbed by the paper conveying felt. The paper machine is divided into a roll press type paper machine and a shoe press type paper machine. Among them, in the roll press type paper machine, a pressing device is provided in the press section, and the pressing device clamps and presses the nip between the rolls. Part of the paper transport felt that holds the wet paper. On the other hand, in the shoe press type papermaking machine, a press device is provided in the press section, and the press device pinches and presses a part of the paper conveying felt that pinches the wet paper between the roll and the shoe. In particular, since the shoe press type papermaking machine has a larger press area of the press section (ie the nip) of the press elements than the more widely used roll press type papermaking machine, the press time can thus be extended. Therefore, the shoe press type paper machine can have more excellent dewatering properties.

In the paper machine, the wet paper conveyed by the paper conveying felt of the press device is sequentially conveyed through a plurality of paper conveying felts of the press mechanism arranged in succession, while water is squeezed out therefrom, and then the surface of the wet paper is smoothed. Therefore, the paper conveying felt must have the function of conveying the wet paper, the function of squeezing water out of the wet paper, and smoothly separating the wet paper from the paper conveying felt to send the wet paper to the next process (in other words, The paper separation function to make the wet paper easy to peel off from the paper conveying felt, and the wet paper surface smoothing function to smooth the surface of the wet paper. In particular, since a large amount of moisture is squeezed out from the wet paper through the press mechanism arranged on the upstream side in the wet paper conveying direction of the press section, the paper conveyance of the press mechanism arranged on the downstream side in the wet paper conveying direction For felts, the more important function is the smoothing function of the wet paper surface than the function of squeezing water from the wet paper.

On the portion covering the center of the press section of the press mechanism to its outlet, since the pressure applied to the wet paper and paper conveying felt is released suddenly, the volume of the paper conveying felt and wet paper expands rapidly at this portion. As a result, a negative pressure is generated on the paper conveying felt and the wet paper, and since the wet paper is composed of fine fibers, capillary phenomenon occurs, thereby causing a rewetting phenomenon in which moisture absorbed by the paper conveying felt is transferred to the wet paper again. In this way, the portion covering the center of the press section of the press mechanism to the outlet thereof becomes an important factor for dehydrating the dewatering performance of the press device of the paper machine.

As a paper conveying felt for preventing the rewetting phenomenon and the blowing phenomenon of the paper conveying felt at the time of pressing, there is known a paper conveying felt which is impregnated with an emulsified resin and whose wet paper side portion has been intensively studied (See US Patent No. 4,500,588). More specifically, in a paper conveying felt, a batt layer formed on the surface of a base layer is impregnated with an emulsified resin, while calendering is performed on the wet paper side surface of the batt layer to form a suede-like dense and a smooth surface to form a barrier layer, or to impregnate the thick fiber layer formed on the surface of the base layer with an emulsified resin to form a barrier layer (non-woven fabric fiber layer) on the thick fiber layer, and to form a barrier layer (non-woven fiber layer) on the barrier layer (without A fine fiber layer is formed on the spun fiber layer). Therefore, since the barrier layer prevents the emulsified resin from permeating to the wet paper side surface of the paper conveying felt, rewetting and foaming of the paper conveying felt can be prevented, and thus the papermaking speed can be increased. In addition, factors hindering the smoothing of the surface of wet paper can be reduced when the paper conveying felt is pressed together with wet paper in the press section of the press mechanism, in which air contained in the paper conveying felt is squeezed out from the wet paper side surface To roughen the surface of wet paper.

In addition, a paper conveying felt provided with a liquid-impermeable layer on its surface is also known (see German Utility Model Application Publication No. DE 29706427 U1). The paper conveying felt has a fiber layer including thermoplastic fibers or fused fibers which are melted by heating the surface of the fiber layer to form a liquid-impermeable layer.

In addition, there is known a paper conveying felt in which the surface of the resin layer facing the wet paper has gaps opening upward (see Patent Document 3). In paper conveying felts, in order to improve abrasion resistance, release properties, and compressive strength, a plurality of layers are formed in the polymer resin layer facing the wet paper by dissolving solvent-removable substances (specifically, solvent-removable fibers). Open grooves, whereby water permeability is obtained by utilizing gaps formed in the wet paper-facing polymer resin layer (more specifically, the cured polymer resin layer) through the plurality of open grooves.

US Patent No. 4,500,588, German Utility Model Application Publication No. DE29706427 U1, and JP-A-62-21895 are referred to as prior art.

Paper transport felts mounted on multiple press units arranged in series have different primary functions. The function of squeezing water from the wet paper is mainly required for the paper conveying felt installed on the press mechanism arranged on the upstream side along the wet paper conveying direction among the plurality of press mechanisms, while for the paper conveying felt installed on the press mechanism arranged on the upstream side along the wet paper conveying direction The paper conveying felt on the press mechanism on the downstream side mainly requires the function of smoothing the wet paper surface. That is, the surface smoothness of the wet paper mainly depends on the paper conveying felt installed on the press mechanism disposed on the downstream side in the wet paper conveying direction among the plurality of press mechanisms. Thus, the paper conveying felt installed on the press mechanism disposed on the downstream side in the wet paper conveying direction among the plurality of press mechanisms must have a smooth surface facing the wet paper. However, since the wet paper input to the press mechanism arranged on the downstream side in the wet paper conveying direction among the plurality of press mechanisms contains a little moisture, it is preferable that the paper conveying felt installed on the press mechanism arranged on the downstream side Must be more or less dehydrating.

The moisture contained in the wet paper is absorbed and squeezed out by the paper conveying felt which is compressed and restored in the press section of the press mechanism. That is, in order to effectively squeeze out water, the paper transfer felt needs to have appropriate air permeability, compressibility, and recovery.

In the press arrangement of a paper machine, especially in a shoe press type paper machine or a single nip type paper machine, due to the press section (i.e. the nip) of the press element exerts a very large force on the paper transport felt. The pressure is to squeeze the water, so the batt layer of the paper conveying felt directly in contact with the press section of the press is easily damaged and thus the life of the paper conveying felt (ie, the usable time of the paper conveying felt) is shortened. For this reason, the maintenance of periodic replacement|exchange of a paper conveyance felt is required.

In addition, in the press device of the paper machine, due to the high pressure and high friction of the press section (ie, the nip), the fibers on the batt layer of the paper conveying felt that directly contacts the wet paper are seriously shed (fiber loss) or broken off. Most of these shed or broken fibers exit the press through cleaning units such as water jets and suction boxes, however, some fibers may adhere to the surface of the wet paper. Since the fibers that fall off or fall off are thicker and harder than those of wet paper, paper (i.e., paper products) made of wet paper to which fibers fall off or fall off is adhered has poor printability (specifically, when printing cause discoloration). As a result, the quality of paper products such as printed matter deteriorates due to the fibers that come off from the surface of the batt layer of the paper conveying felt that directly contacts the wet paper. In addition, since the detached fibers roughen the surface of the wet paper side batt, it becomes a factor of lowering the smoothness of the wet paper surface.

However, it is difficult to replace only the fibers constituting the surface of the batt layer of the paper conveying felt which is in direct contact with wet paper with fine fibers. In particular, as a process for manufacturing a paper conveying felt, when fine fibers are cut in a process preceding the needling process (cutting operation is performed before the needling process, and a fiber web is generated by needling after the cutting operation), it is easy Fibrous clumps (ie clumps of fibers) are generated. Thus, fiber lumps are formed on the felt by needling immediately after the cutting operation, so that relatively large irregularities are formed on the surface of the paper conveying felt, thereby degrading the surface smoothness of the wet paper.

U.S. Patent No. 4,500,588 discloses a paper conveying felt whose wet paper side surface is treated. side surface), but poor performance in squeezing water from wet paper. Therefore, such a paper conveying felt cannot be expected to have high performance of dewatering from wet paper, so it is preferable to use a paper conveying felt in which dewatering of wet paper is performed entirely by a pressing mechanism arranged on the upstream side in the wet paper conveying direction. In other words, the paper conveying felt disclosed in U.S. Patent No. 4,500,588, in which the calendering process is performed on the wet paper side surface, may be preferably installed in a plurality of press mechanisms arranged in series on the downstream side in the wet paper conveying direction. on the pressing device. However, it is important to remove as much water as possible from the wet paper in the press section because the heating and drying process in the dryer section as a subsequent process requires a large amount of thermal energy. Therefore, the paper conveying felt installed on the press mechanism disposed on the downstream side in the wet paper conveying direction among the plurality of press mechanisms more preferably has a function of squeezing water from the wet paper more or less. The paper conveying felt disclosed in U.S. Patent No. 4,500,588 (wherein a non-woven fiber layer is interposed between a coarse fiber layer facing the base layer and fine fibers facing the wet paper, and has fiber masses) is not suitable for use as such Press units of paper machines where a high capacity to squeeze water from wet paper is required on the paper transfer felt.

In the paper conveying felt disclosed in German Utility Model Application Publication No. DE 29706427 U1, the liquid-impermeable layer is formed by heating the surface of the fiber layer containing thermoplastic fibers or molten fibers to melt the thermoplastic fibers or molten fibers. Paper transport felts are characterized by the ability to control the thickness of the liquid impermeable layer to some extent by adjusting the amount of heat applied from the surface of the fibrous layer. However, since it is necessary to heat within a range that does not deteriorate the fiber properties of the heated surface, that is, the surface of the liquid-impermeable layer, the depth of the paper conveying felt (i.e., the thickness of the liquid-impermeable layer) is limited by heating in consideration of the thermoplastic fiber Or the thermal deterioration or thermal decomposition of the molten fiber is limited. Thereby, the thickness of the liquid-impermeable layer is automatically limited so as not to be too thick. In addition, since the wet paper side surface includes a fiber layer, very large pressure or frictional force is applied to the fibers by the press section, so that detachment or breaking of fibers on the surface of the fiber layer (ie, fiber loss) occurs significantly. Fiber loss at the surface of the fibrous layer in the paper transport felt that is in direct contact with the wet paper deteriorates the quality of paper products such as printed matter. On the other hand, due to fiber loss, the surface of the fiber layer becomes rough, so the surface smoothness of the wet paper is significantly reduced.

In the paper conveying felt disclosed in Patent Document 3, since elongated gaps are formed on the surface of the polymer resin layer facing wet paper by the dissolution of solvent-removable substances (specifically, solvent-removable fibers), the dehydration There is no change in performance. However, when the amount of the solvent-removing substance is increased, the surface smoothness of the wet paper is affected. In addition, since the solvent-removable substance serving as a reinforcing substance is removed from the polymer resin layer facing the wet paper after the solvent-removable substance is dissolved, compression resistance deteriorates.

Contents of the invention

An object of the present invention is to provide a paper conveying felt which is less damaged by the pressing of the pressing member of the pressing mechanism and has excellent durability, suitable dehydration, and excellent wet paper surface smoothness. It is also an object to provide a press arrangement of a paper machine having such a paper transport felt.

The present invention provides a paper conveying felt, which is at least one of a pair of paper conveying felts arranged in a press device in a press section of a paper machine, which together with a press member in the press device constitutes a press A mechanism for conveying wet paper while clamping and pressing it by the pressing member, having: a base layer; a first batt layer formed on the wet paper side surface of the base layer; a second batt layer formed on the press side surface of the base layer; a polymer elastic material impregnated in the base layer, the first batt layer, and the second batt layer; and a wet paper contact layer formed on the wet paper side surface of the first batt layer so as to contact the wet paper direct contact, and comprising a flexible resinous material, wherein the wet paper contact layer is more compressible than the layer formed by the base layer, the first batt layer, and the second batt layer.

In the paper conveying felt, the resin material includes foamed resin or hollow granular resin.

In a paper conveying felt, under a pressure of 10 kg/cm ² , the difference between the compressibility of the wet paper contact layer and the layer formed by the base layer, the first batt layer, and the second batt layer is greater than Or equal to 5%.

The present invention also provides a press apparatus for a paper machine having a paper transport felt as described above.

The present invention also provides a press device of a paper machine, which has a plurality of press mechanisms each having a paper conveying felt, wherein the plurality of press mechanisms are continuously arranged along a wet paper conveying direction conveyed by the paper conveying felt.

In a press apparatus of a paper machine, the aforementioned paper conveying felt is provided in a press mechanism provided on a downstream side in a conveying direction among a plurality of press mechanisms.

The aforementioned press of the paper machine may be a press of a shoe press type paper machine, wherein the press of the press is a shoe press having a roll of a press paper conveying felt and a shoe.

The aforementioned press of the paper machine may be a press of a roll press type paper machine, wherein the press of the press is a roll press having a pair of roll presses to press the paper delivery felt.

In the paper conveying felt, the base layer, the first batt layer, and the second batt layer include a polymer elastic material, and the wet paper contact layer is formed of a flexible resin material. Thus, since the base layer, the first batt layer, and the second batt layer include polymer elastic material such as synthetic resin, the base layer and the second batt layer have high mechanical strength against being pressed by the pressing member of the pressing mechanism. Therefore, even when the paper conveying felt is strongly pressed by the press portion of the press member, the paper conveying felt is rarely damaged, so that the paper conveying felt has excellent durability. As a result, the frequency of replacement of the paper transfer felt can be reduced due to the extended life of the paper transfer felt. In addition, since the wet paper contact layer made of flexible resin material has greater compressibility than the layer formed by the base layer, the first batt layer, and the second batt layer, it is different from the layer formed by the base layer, the first batt layer, and the Compared with the layer formed by the second batt layer, the wet paper contact layer has appropriate compression and recovery properties, so it can absorb moisture from the wet paper. In addition, since the wet paper contact layer does not generate fiber shedding at all, the surface smoothness of the wet paper is improved. In addition, since the wet paper contact layer does not shed fibers, the service life of the paper conveying felt (ie, the lifespan of the paper conveying felt) is extended, and the frequency of replacement can be reduced.

In the paper conveying felt, since the resin material forming the wet paper contact layer contains foamed resin or hollow granular resin, the wet paper contact layer has a smooth and porous internal structure. In this way, the paper conveying felt is moderately cushioned and has the ability to dewater, so that the surface of the wet paper can be smoothed.

In a paper conveying felt, under a pressure of 10 kg/cm ² , due to the difference between the compressibility of the wet paper contact layer of the paper conveying felt and the compressibility of the layer formed by the base layer, the first batt layer, and the second batt layer The difference between them is greater than or equal to 5%, so the wet paper contact layer has moderate compression and recovery. In addition, the paper transport felt is more suitable for use downstream in the transport direction of the press.

The polymer elastic material may be a synthetic resin such as water-based polyurethane resin, water-based acrylic resin, water-based epoxy resin, and water-based synthetic rubber (ie, water-based emulsified resin). Such a polymer elastic material is impregnated in the base layer, the first batt layer, and the second batt layer, and then heated and cured.

The above-mentioned good operating advantages are obtained because the press unit of the paper machine includes a paper machine belt.

In addition, when the press apparatus of the paper machine including a plurality of press mechanisms having the aforementioned paper conveying felt, the plurality of press mechanisms are successively arranged in the direction in which the wet paper is conveyed by the paper conveying felt, water can be extracted from the wet paper efficiently, and the wet The paper surface can be moderately smoothed, so that papermaking can be performed at high speed.

In addition, when the paper conveying felt is provided in a press mechanism disposed on the downstream side in the conveying direction among a plurality of press mechanisms, it is considered that the water permeability is slightly lower than that of a paper conveying felt having a smaller content of polymer elastic material, but since there is a more excellent Excellent wet paper surface smoothing function, so the surface smoothness of wet paper can be improved, and papermaking can be performed at high speed.

In the press apparatus of the press type paper machine shown, since the press area of the press section (i.e., the nip formed between the roll and the shoe) is widened by using the press apparatus of the shoe press type paper machine, thereby The pressing time can be extended, so the dewatering performance and the smoothness of the wet paper surface can be improved.

In the press apparatus of the roll press type papermaking machine, even if the press apparatus of the roll press type papermaking machine is used, the same excellent operational advantages as described above can be obtained.

Therefore, it is possible to provide a paper conveying felt that causes little damage due to the pressing of the pressing member of the pressing mechanism, has excellent durability, appropriate dehydration, and has excellent surface smoothness of wet paper, and has the paper conveying felt. The press device of the paper machine.

The present invention has been briefly described above. The present invention will be more apparent by describing the best mode for carrying out the invention with reference to the accompanying drawings.

Description of drawings

1 is a longitudinal sectional view showing a paper conveying felt according to an embodiment of the present invention; and

Fig. 2 is a plan view schematically showing the structure of a press device of a paper machine according to an embodiment of the present invention.

Detailed ways

Hereinafter, several preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a longitudinal sectional view (paper conveying felt 100) showing a paper conveying felt according to an embodiment of the present invention, and FIG. 2 is a plan view schematically showing the structure of the paper conveying felt according to an embodiment of the present invention.

As shown in FIG. 1 , the paper conveying felt 100 includes a base layer 11 , a batt layer 13 (a first batt layer 13A and a second batt layer 13B), and a wet paper contact layer 25 . Specifically, the first batt layer 13A is formed on the wet paper side surface of the base layer 11, and the press member side surface of the base layer 11 (specifically, the surface facing one of the pair of rollers or one of the roller and the shoe) The second batt layer 13B is formed on the first batt layer 13A, and the wet paper contact layer 25 is formed on the wet paper side surface of the first batt layer 13A so that the wet paper contact layer 25 directly contacts the wet paper. The base layer 11 and the batt layer 13 (the first batt layer 13A and the second batt layer 13B) are entangled with each other by a needling operation to be integrated.

The base layer 11 is used to impart strength to the paper conveying felt 100 and it may suitably be made of a woven fabric such as Nylon 6 (i.e. N6) and nylon 66 (ie N66) synthetic fibers, or natural fibers such as wool, cloth made of overlapping thread materials rather than woven, or made into sheet-shaped cloth. In this embodiment, woven cloth is used for the base layer 11 .

The wool layer 13 (the first wool layer 13A and the second wool layer 13B) is a non-split fiber layer (non-split fiber layer) formed by artificial fibers 17 with a size of 6 decitex or more (generally about 17 decitex). ). The material forming the batt layer 13 may suitably include the same material as that of the base layer 11 . The second batt layer 13B may be omitted depending on the desired properties of the paper transfer felt 100 .

The base layer 11 , the first batt layer 13A, and the second batt layer 13B contain a polymer elastic material 23 in the fibers thereof or in spaces between the artificial fibers 17 . Examples of the polymer elastic material 23 may include synthetic resins such as water-based polyurethane resin, water-based acrylic resin, water-based epoxy resin, and water-based synthetic rubber (ie, water-based emulsion resin). The polymer elastic material 23 is spread on the surface (lower surface in FIG. 1 ) of the second batt layer 13B by use of a roller or a coater blade or by spraying the polymer elastic material thereon by use of a sprayer, thereby Such a polymer elastic material 23 is impregnated into the second batt layer 13B, the base layer 11, and the first batt layer 13A, and then dried and cured by using hot air. Since the base layer 11, the first wool layer 13A, and the second wool layer 13B contain the polymer elastic material 23, the interlacing points of the fibers constituting the base layer 11, the first wool layer 13A, and the second wool layer 13B are mutually compatible with each other. The bioelastic material 23 is combined, thereby stabilizing the shape and improving the mechanical strength. That is, even when the paper conveying felt 100 is pressed in the press section of the press mechanism, it is not flattened for a long time and its density and air permeability tend to be stable with little change over time.

The wet paper contact layer 25 is formed of a flexible resin layer formed on the wet paper side surface of the first batt layer 13A. The resin material forming the resin layer is, for example, a resin material including foamed resin, hollow fine particle resin, etc., and makes the resin layer soft. The compressibility of the wet paper contact layer 25 is greater than that of the portion (layer) of the paper transfer felt 100 formed by the base layer 11, the first batt layer 13A, and the second batt layer 13B.

More specifically, the compressibility of the wet paper contact layer 25 ranges between 25% and 40%, and preferably between 30% and 35%. On the other hand, the compressibility of the portion (layer) of the paper conveying felt 100 formed by the base layer 11, the first batt layer 13A, and the second batt layer 13B ranges from 20% to 35%, and is preferably between 25% to 30%.

Compressibility was obtained using a platen tester (not shown), a test piece of the paper conveying felt 100 was pressurized at an initial pressure of 2 kg/cm ² and then the pressure was increased to 10 kg/cm ² while passing through the optical The image output of the microscope measures each thickness of the wet paper contact layer 25 and the portion (layer) of the paper conveying felt 100 formed by the base layer 11, the first batt layer 13A, and the second batt layer 13B. The compressibility is then obtained by substituting the measured thickness into the following expression. Each of the plurality of test pieces of the paper transfer felt 100 was subjected to the same tests as previously described. In addition, in the foregoing test, an initial pressure is applied to the test piece so that by smoothing the surface of the test piece, the measurement of thickness will not be erroneous.

The expression for calculating the compressibility is as follows.

Compressibility (%)=(t1-t2/t1)×100

(where t1 is the thickness of the test piece under a pressure of 10kg/ ^cm2 , and t2 is the thickness of the test piece under a pressure of 2kg/ ^cm2 )

In addition, in the above test, even if the test piece of the paper conveying felt 100 itself is used as a test piece, it is difficult to measure the wet paper contact layer and the paper formed by the base layer 11, the first batt layer 13A, and the second batt layer 13B. The individual thickness of the portion (layer) of the felt 100 is conveyed. More specifically, only layering the paper conveying felt 100 is very difficult for the wet paper contact layer 25 and the portion (layer) of the paper conveying felt 100 formed by the base layer 11, the first batt layer 13A, and the second batt layer 13B. It is difficult to respectively obtain a test piece having a uniform thickness.

The foamed resin is formed by foaming such as water-based polyurethane resin, water-based acrylic resin, and water-based epoxy resin, or by mixing a foaming agent in the resin to mix a plurality of fine bubbles in the resin. The wet paper contact layer 25 contains a large number of fine air cells 27 and has a high degree of flexibility and a smooth surface.

The resin containing the hollow fine particle resin is formed by mixing a hollow fine particle resin such as thermally expandable microcapsules with a resin containing water-based polyurethane resin, water-based acrylic resin, and water-based epoxy resin. Thermally expandable microcapsules are tiny plastic spheres (for example, with an average particle size of 10-17 μm) produced in a polymer shell containing liquid gas, and are hollow spherical particles that expand in volume when heated to 80-190 °C About 40 times or so. Thus, the wet paper contact layer 25 contains a plurality of air cells 27 . The wet paper contact layer 25 containing heat-expandable microcapsules has improved softness, surface smoothness, and dimensional stability. "EXPANCEL" (trademark; manufactured by Nippon Ferrite Co., Ltd.) can be exemplified as heat-expandable microcapsules.

The basis weights of the constituent elements of the typical example of the paper conveying felt 100 having the above-mentioned structure were measured: the basis weight of the wet paper contact layer 25 was 200 g/m ² , the basis weight of the first batt layer 13A was 400 g/m ² , the base layer 11 The basis weight of the second batt layer 13B is 650 g/m ² , and the basis weight of the second batt layer 13B is 100 g/m ² . The polymer elastic material 23 impregnates the base layer 11 , the first batt layer 13A, and the second batt layer 13B by 5 wt % respectively, and does not impregnate the wet paper contact layer 25 .

The basis weights of the constituent elements of a lightweight example of the paper delivery felt 100 were measured: the basis weight of the wet paper contact layer 25 was 100 g/m ² , the basis weight of the first batt layer 13A was 200 g/m ² , the basis weight of the base layer 11 was The weight is 200g/m ² , and the second batt layer 13B is omitted. The polymer elastic material 23 impregnates 1 wt % into the base layer 11 and the first batt layer 13A respectively, and does not impregnate into the wet paper contact layer 25 .

The basis weight of each constituent element of a heavy example of the paper transfer felt 100 was measured: the basis weight of the wet paper contact layer 25 was 300 g/m ² , the basis weight of the first batt layer 13A was 800 g/m ² , the basis weight of the base layer 11 was The weight was 1500 g/m ² , and the basis weight of the second batt layer 13B was 300 g/m ² . The polymer elastic material 23 impregnates 10 wt % into the base layer 11 , the first batt layer 13A, and the second batt layer 13B respectively, and does not impregnate into the wet paper contact layer 25 .

A method of manufacturing the paper conveying felt 100 will be briefly described. First, both sides of the woven base layer 11 are integrally formed with the fleece layer 13 by methods such as needle punching. In the case of using a foamed resin for forming the wet paper contact layer 25, the wet paper contact layer 25 (ie, resin layer) is formed by coating the foamed resin on the wet paper side surface of the first batt layer 13A and then drying . Meanwhile, in the case of using a resin containing heat-expandable microcapsules for forming the wet paper contact layer 25, the wet paper contact layer 25 (i.e., resin layer) is coated on the wet paper side surface of the first batt layer 13A containing The resin of the heat-expandable microcapsules is formed by expanding the heat-expandable microcapsules by heating and drying.

Next, the polymer elastic material 23 is applied to the surface of the second batt layer 13B (in FIG. On the bottom surface in), therefore, the polymer elastic material 23 is impregnated into the second batt layer 13B, the base layer 11, and the first batt layer 13A, and then dried and cured by using hot air. The amount of the polymer elastic material 23 impregnated in the base layer 11, the first batt layer 13A, and the second batt layer 13B is appropriately selected according to the required characteristics of the press mechanism equipped with the paper conveying felt 100.

Therefore, the base layer 11, the first batt layer 13A, and the second batt layer 13B having excellent durability, less compressibility, and recovery are formed; The wet paper contact layer 25 has greater compressibility and recovery than 13B.

In order to obtain optimum performance for the different types of paper to be manufactured, the respective types of fibers forming the base layer 11 and the batt layer 13, the type and amount of the resin material forming the wet paper contact layer 25, and the polymerization The type and impregnation amount of the bioelastic material 23 are appropriately selected in consideration of characteristics for each case or a combination thereof.

Next, a press device 300 of a paper machine (shoe press type paper machine) equipped with an endless belt-shaped paper conveying felt 100 will be described with reference to FIG. 2 .

As shown in Figure 2, the press device 300 is called a closed traction press device 300, in which two mechanisms, namely the first press mechanism 51 and the second press mechanism 53, are aligned along the conveying direction of the wet paper W (the direction shown by the arrow A). ) are arranged consecutively. By using a closed-draw type paper machine in which wet paper W is conveyed in a state sandwiched between two pairs of paper conveying felts 100 and pressed, it can stably convey wet paper W at a high speed of 1200 to 1400 m/min. Thereby, higher efficiencies are possible compared to open-draw paper machines.

The first press mechanism 51 includes a pair of paper conveying felts 100 and a first shoe 55 and a first roll 57 (in other words, a first shoe press), which are opposed to each other to form a first nip therebetween (in other words, a first nip). In other words, the first press section). The second press mechanism 53 includes a pair of paper conveying felts 100 and a second shoe 59 and a second roll 61 (in other words, a second shoe press), which are opposed to each other to form a second nip therebetween (in other words, a second press). In other words, the second press section).

As shown in Figure 2, the paper conveying felt 100 can be used as the upper and lower paper conveying felts of the first press mechanism 51 and the second press mechanism 53 respectively, but it can also be used as the upper and lower felts of the first press mechanism 51 and the second press mechanism 53. Use any one of the lower paper conveying felts. When the paper conveying felt 100 is assembled as any one of the upper and lower paper conveying felts of the first press mechanism 51 and the second press mechanism 53, any paper conveying felt can be used as the other paper conveying felt according to papermaking characteristics. In addition, generally, a paper conveying felt whose surface is smoother than dehydrating is used as a pair of paper conveying felts mounted on the second press mechanism 53 provided on the downstream side. Therefore, preferably, the pair of paper conveying felts 100 are used as the paper conveying felts of the second press mechanism 53 .

As shown in FIG. 2 , the wet paper W conveyed from the wire section (not shown) to the first press mechanism 51 is sandwiched between a pair of paper conveying felts 100 and conveyed therebetween, by using the first shoe 55 And the first 57 squeezes the wet paper, water is squeezed out of the wet paper, and the squeezed water is sucked into the wet paper contact layer 25 of the paper delivery felt 100 . Next, the wet paper W is conveyed to the second pressing mechanism 53, and is sandwiched between a pair of paper conveying felts 100 and conveyed therebetween, by squeezing the wet paper with the second shoe 59 and the second roller 61, the water Further squeezed from the wet paper, the squeezed water is sucked into the wet paper contact layer 25 of the paper transport felt 100 .

The wet paper contact layer 25 of the paper conveying felt 100 is formed of a flexible resin material, and its surface facing the wet paper is dense and smooth. Thus, the wet paper W formed to have a smooth surface is conveyed to a drying section (not shown), and then dried therein. Due to the second batt layer 13B, the base layer 11 , and the A batt 13A contains polymer elastic material 23, so that its mechanical strength is increased and these parts are not damaged by the intense pressure in the press section. Therefore, the paper conveying felt has excellent durability.

As mentioned above, the press device 300 of the shoe press type paper machine having the two-stage press mechanism 51 and 53 has been described as an example of the press device of the paper machine according to the present invention, but the present invention can of course also be applied to the press device having A pressing device with one pressing mechanism or a pressing device with a plurality of pressing mechanisms arranged in series.

Here, for easier understanding of the present invention, the structure of a paper conveying felt according to an embodiment of the present invention and the structure of a press apparatus of a paper machine having the paper conveying felt will be briefly described.

The paper conveying felt 100 is at least one of a pair of paper conveying felts arranged in a press device 300 provided in a press section of a paper machine, and in the press device, it is connected with a press member (roll 57 or 61 and The shoe 55 or 59) together form a press mechanism 51 or 53 which holds the wet paper W for conveyance and is pressed by said press. The paper conveying felt 100 includes a base layer 11; a first batt layer 13A formed on the wet paper side surface of the base layer 11; a second batt layer 13B formed on the wet paper side surface of the base layer 11; a polymer elastic material 23, which is impregnated in the base layer 11, the first batt layer 13A, and the second batt layer 13B; and the wet paper contact layer 25 formed on the wet paper side surface of the first batt layer 13A so as to be in direct contact with the wet paper W, and Features soft resin material. The compressibility of the wet paper contact layer 25 is greater than that of the layer formed by the base layer 11, the first batt layer 13A, and the second batt layer 13B.

In addition, the soft resin material of the wet paper contact layer 25 contains foamed resin or granular resin.

In addition, under the pressure of 10 kg/cm ² , the difference between the compressibility of the wet paper contact layer 25 and the compressibility of the layer formed by the base layer 11, the first batt layer 13A, and the second batt layer 13B is preferably greater than or equal to 5%.

The press device 300 includes a plurality of press mechanisms having the paper conveying felt 100 , and the plurality of press mechanisms 51 and 53 are arranged in series along the wet paper conveying direction A, wherein the wet paper is conveyed by the paper conveying felt 100 .

As described above, according to the present invention, the paper conveying felt 100, the base layer 11, the first batt layer 13A, and the second batt layer 13B comprise the polymer elastic material 23 and the wet paper contact layer 25 is composed of a flexible resin material. Thus, since the base layer 11, the first batt layer 13A, and the second batt layer 13B include the polymer elastic material 23 such as synthetic resin, the base layer and the second batt layer have high mechanical strength against the force of the pressing mechanism 51 and 53. The pressure of the press piece. Therefore, even when the paper conveying felt 100 is strongly pressed by the press portion of the press member, the paper conveying felt is rarely damaged and thus the paper conveying felt has excellent durability. As a result, since the life of the paper conveying felt 100 is extended, the frequency of replacement of the paper conveying felt can be reduced. In addition, since the wet paper contact layer 25 made of a flexible resin material has greater compressibility than a layer composed of the base layer 11, the first batt layer 13A, and the second batt layer 13B, and is more compact than the layer composed of the base layer 11. The layer composed of the first batt layer 13A and the second batt layer 13B has appropriate compressibility and decompression properties, so it can absorb moisture from wet paper. In addition, since fiber detachment from the wet paper contact layer 25 does not occur, the smoothness of the wet paper surface is improved. In addition, as described above, since fibers do not come off from the wet paper contact layer 25, the life of the paper conveying felt 100 (ie, the usable period of the paper conveying felt 100) can be extended and the frequency of replacement can be reduced.

In addition, because under the pressure of 10 kg/cm ² , the difference between the compressibility of the wet paper contact layer 25 and the compressibility of the layer composed of the base layer 11, the first batt layer 13A, and the second batt layer 13B is greater than or is equal to 5%, so the paper transport felt 100 has suitable compressibility and recovery.

According to the press device 300 of the paper machine of the present invention, when a plurality of press mechanisms 51 and 53 having the paper conveying felt 100 are arranged continuously along the wet paper conveying direction in which the wet paper W is conveyed by the papermaking conveying belt 100, the water from the wet paper W are efficiently extruded, and the surface of wet paper can be properly smoothed, so that the papermaking operation can be carried out at high speed. When the paper conveying felt 100 is provided in the pressing mechanism 53 arranged on the downstream side in the wet paper conveying direction in which the paper conveying felt 100 conveys the wet paper W among the plurality of press mechanisms 51, 53, although water permeability is considered relatively The paper conveying felt of the polymer-less elastic material 23 has slightly lower water permeability, but since it has a better function of smoothing the surface of the wet paper, it can improve the surface smoothness of the wet paper W and enable high-speed papermaking operations. In addition, since the paper conveying felt 100 has a dehydrating function, even when the paper conveying felt is attached to the press mechanism 53 arranged on the downstream side, the paper conveying felt can absorb moisture from the wet paper W and can convey the wet paper to the next step. The drying part of the process, thereby reducing the heat consumed in the drying process using hot air.

The present invention is not limited to the above-mentioned embodiment, and it can be appropriately modified and changed in form. In addition, the material, shape, size, numerical value, form, quantity, arrangement position, etc. of each constituent element in the above-mentioned embodiments may be arbitrary and not limited, as long as the present invention can be realized.

For example, when the paper conveying felt according to the present invention is installed on a press device of an open-draw shoe press type paper machine having a section for independently conveying wet paper W during conveying, the same advantages can be equally effectively obtained . Furthermore, the operational advantages of the invention described above can also be obtained when the paper transport felt according to the invention is installed on a press of a paper machine of the roll press type with a closed draw or an open draw.

Claims (6)

1. paper transporting felt, be at least one in a pair of paper transporting felt, described paper transporting felt is disposed in the pressing device set on the press section of paper machine, squeezing part in described pressing device forms press mechanism, its clamping that l Water Paper is carried and by described squeezing part it is pressurizeed, and comprising:

Basic unit;

First batt, it is formed on the wet paper surface of described basic unit;

Second batt, it is formed on the squeezing part side surface of described basic unit;

The polymer elasticity material, it impregnated in described basic unit, described first batt, reaches in described second batt; And

The l Water Paper contact layer, thus it is formed on the wet paper surface of described first batt and directly contacts with described l Water Paper, and comprise the flexibility resin material;

Wherein, the compressibility of described l Water Paper contact layer than by described basic unit, described first batt, and described second batt forms layer compressibility big.

2. paper transporting felt according to claim 1, wherein, described flexibility resin material comprises the particulate resins of Foamex or hollow.

3. paper transporting felt according to claim 1, wherein, at 10kg/cm ²Pressure under, the compressibility of described l Water Paper contact layer and by described basic unit, described first batt, and described second batt forms layer compressibility between difference more than or equal to 5%.

4. the pressing device of a paper machine comprises paper transporting felt according to claim 1.

5. the pressing device of a paper machine, comprise a plurality of each all have the press mechanism of paper transporting felt according to claim 1, wherein, described a plurality of press mechanisms are along carrying the throughput direction of l Water Paper to arrange continuously by described paper transporting felt.

6. the pressing device of a paper machine, wherein, described pressing device comprises a plurality of press mechanisms, and paper transporting felt according to claim 1 is set on the press mechanism in the downstream that is arranged at described throughput direction in described a plurality of press mechanism.